All you need for this is a needle, thread, and stretch fabric that doesn’t fray when you cut it. I used performance fabrics, which works fine if you leave edges un-hemmed.

Today as my demonstrating model I have Miss Clawdeen! 😀

First, cut a piece of the stretch fabric that can wrap around your doll with a bit of seam allowance, and can reach from her bust to her upper thighs.

Flip the fabric over so that the wrong side is facing outwards, and sew a seam down the back, contouring to the doll’s body.

Next, take a few stitches between the doll’s legs, leaving space for her feet to come through. You can remove the suit from the doll to help, or leave it on.

Now turn it inside out, and voila!

Next, cut a piece of stretch fabric in a contrasting color (or the same color, if you wish). It should be the width the you want the neck strap to be, and should reach from the doll’s shoulder to her knees.

Now, sew each end of the strap to the bust of the suit. I’ve done it here in a yellow thread so that you can see it better, but ideally you would do it in a matching color. 🙂

Next, cut the strap in the middle of the back.

Now, weave the needle up through the bust (I learned this awesome trick from My Froggy Stuff 🙂 ), and tie the ends of the thread in a tight knot to create a sweetheart neckline.